Curling brooms influence a curling rock's trajectory as it slides over the ice toward a desired position. The broom or brush is used to ‘sweep’ or brush the ice immediately in front of the rock to heat the ice surface above the ambient temperature. Sweeping also clears unwanted debris out of the path. By heating the ice surface the friction between the rock and the ice is reduced, making the rock run farther on its current path and straighter. The effectiveness of sweeping depends on the amount by which the ice surface is heated via the friction of the sweeping broom: more heat, more effect.
A curling broom consists of a shaft or handle, a receptacle, and a removable, replaceable head as shown in FIG. 1. The shaft is held by the curler during the sweeping motion and the broom head contacts the ice. The head is most commonly attached to the receptacle via two bolts and threaded holes, bolts and nuts, or hook and loop. The broom head is most commonly constructed on a base that is usually made of plastic (FIG. 2) many other materials including wood may also be used. The base may be many shapes from round to triangular including wings that give a boomerang appearance. A common type current being used is an ovoid with a long axis of approximately 220 mm, short axis of approximately 65 mm and thickness of 10 mm. The underside of the base has a layer of foam which may be bonded in place. This foam layer is for shock absorption and for spreading the head pressure evenly over the ice surface. This can be made to various thicknesses ranging from 2 mm to 50 mm depending on the preference of the player, or there may be no foam layer at all. The foam may be in layers or combined with other materials. Some embodiments have more than one type of foam in various densities and thicknesses. The geometry of the foam can be simply flat or a more complex three dimensional surface with protrusions, indents or gaps. Over the foam is a layer of woven fabric, most often Cordura nylon or other synthetic, polymeric weave. The fabric can be of any colour or pattern. The fabric may be stapled to the top-side of the base (see dotted path in FIG. 2 and FIG. 3) to hold it in place. However, the exterior cloth may be bonded directly to the foam and the foam attached to the receptacle by hook and loop. Other methods may be used to attach the cloth. The fabric may or may not be glued to the foam layer.
Since one of the roles of the curling broom head is to heat the surface of the ice, it would be very advantageous to provide a curling broom that has a broom head that can increase the heat flow into the surface of the ice.